Nanographite impurities within carbon nanotubes are responsible for their stable and sensitive response toward electrochemical oxidation of phenols

Electrochemists employ carbon nanotube surfaces to achieve highly stable and sensitive electrochemical detection of phenols. There is a large amount of interest in the electrochemical oxidation of phenolic compounds, especially for environmental detection. Herein, we investigate the reasons behind the observed stable and sensitive response on carbon nanotube surfaces. We unambiguously demonstrate that the reported stability and sensitivity exhibited by CNTs is not actually 'inherent' to CNT materials but is instead caused by the nanographite impurities contained within them. These findings will have profound impact on the way electrochemical sensors are designed.